Smoothness indicator analysis system

ABSTRACT

A method for analyzing roadway information includes receiving a first set of elevation data points defining at least a portion of an existing surface, receiving a second set of elevation data points defining at least a portion of an intended surface, comparing the first set of elevation data points to the second set of elevation data points to determine whether a relative elevation difference exists between corresponding data points of the first set of elevation data points and the second set of elevation data points, and generating an automated report displaying a comparison of the first set of elevation data points to the second set of elevation data points. The report provides information useful for planning pavement projects and/or maintaining the paved road surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 10/876,258, filed Jun. 23, 2004, entitled“SMOOTHNESS INDICATOR,” now abandoned, which in turn is acontinuation-in-part of U.S. patent application Ser. No. 10/098,981,filed Mar. 15, 2002, Publication Number US2003/0175077A1, entitled“METHOD AND APPARATUS FOR CALCULATING AND USING THE PROFILE OF ASURFACE,” published Sep. 18, 2003, now U.S. Pat. No. 7,044,680, issuedon May 16, 2006. The present application herein incorporates all of theabove-identified U.S. Patent Applications by reference in theirentirety.

Further, the present application claims the benefit under 35 U.S.C. §120of U.S. patent application Ser. No. 11/360,464, filed Feb. 23, 2006,entitled “SMOOTHNESS INDICATOR ANALYSIS SYSTEM,” which is hereinincorporated by reference in its entirety.

Further, the present application claims the benefit under 35 U.S.C.§119(e) of U.S. Provisional Application Ser. No. 60/655,278, filed Feb.23, 2005, entitled “SMOOTHNESS INDICATOR ANALYSIS SYSTEM,” which isherein incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to the field of computersoftware, and more particularly, to a smoothness indicator analysissystem for analyzing a profile of a road surface.

BACKGROUND OF THE INVENTION

Methods for finishing paved surfaces such as concrete presently use apaving machine to insert structural steel, slip form a slab, and screedand trowel the slab surface. Because contractors are frequently gradedon the smoothness of the finished surface, it is desirable to profilethe surface for determining whether modifications such as grinding arerequired.

Typically, pavement of a road is completed and the road surface isallowed to set up or cure to a point of hardness such that surfaceprofile measurements may be taken for determining whether the surfacemeets smoothness requirements. The surface profile measurements are usedto calculate index values for the road surface, such as Profile Index(PI) values and International Roughness Index (IRI) values.

After the paved surface has set up, a surface profile is taken with aprofilograph, such as a California profilograph, which is wheeled alongthe road for creating a roughness profile of the road. Then,modifications to the road surface such as grinding may be conducted tomeet specifications. This is a costly technique for altering the roadsurface.

Further, the importance of pavement planning is becoming more evident ascontractors realize that well-planned pavement operations are costeffective. Contractors desire to analyze the subgrade of the roadsurface before the pavement of the road is completed for variousreasons. For example, contractors can save paving material, reduce thecost of concrete slabs, and reduce the cost of road surfacemodifications if they predict an overall estimated volume of pavingmaterial based on subgrade conditions. Contractors also desire topredict repair prone areas for future pavement maintenance by locatingthin or thick spots in a slab before the pavement of a road iscompleted.

Thus, it would be desirable to provide a method for measuring a surfaceprofile while the road surface is in a plastic state, for immediatemodification of the surface as well as correction of paving machinesettings. It would be also desirable to provide a computerizeduser-friendly system to take surface profile data, analyze the same, andgenerate a comprehensive report useful for planning and maintainingpavement.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a smoothness indicatoranalysis system for analyzing elevation information collected andmeasured by a smoothness indicator and generating a comprehensive reportuseful for planning and maintaining pavement of a road.

In a first aspect of the present invention, a method for analyzingelevation profile data useful for planning pavement projects andmaintaining the paved road surface may be provided. A method foranalyzing roadway information comprises receiving a first set ofelevation data points defining at least a portion of an existingsurface, receiving a second set of elevation data points defining atleast a portion of an intended surface, comparing the first set ofelevation data points to the second set of elevation data points todetermine whether a relative elevation difference exists betweencorresponding data points of the first set of elevation data points andthe second set of elevation data points, and generating an automatedreport displaying a comparison of the first set of elevation data pointsto the second set of elevation data points. The report indicates atleast one of (a) a relative high spot on the existing surface when arelative elevation difference exists between corresponding data pointsof the first set of elevation data points and the second set ofelevation data points, (b) a relative low spot on the existing surfacewhen a relative elevation difference exists between corresponding datapoints of the first set of elevation data points and the second set ofelevation data points, or (c) a relative yield of the existing surfaceas compared to the intended surface.

In a second aspect of the present invention, an apparatus for analyzingroadway information comprises means for receiving a first set ofelevation data points defining at least a portion of an existingsurface, means for receiving a second set of elevation data pointsdefining at least a portion of an intended surface, means for comparingthe first set of elevation data points to the second set of elevationdata points to determine whether a relative elevation difference existsbetween corresponding data points of the first set of elevation datapoints and the second set of elevation data points; and means forgenerating an automated report displaying a comparison of the first setof elevation data points to the second set of elevation data points. Thereport indicates at least one of (a) a relative high spot on theexisting surface when a relative elevation difference exists betweencorresponding data points of the first set of elevation data points andthe second set of elevation data points, (b) a relative low spot on theexisting surface when a relative elevation difference exists betweencorresponding data points of the first set of elevation data points andthe second set of elevation data points, or (c) a relative yield of theexisting surface as compared to the intended surface.

In a third aspect of the present invention, a method for analyzingelevation profile data useful for planning pavement projects andmaintaining the paved road surface may be provided. A method foranalyzing roadway information comprises receiving a plurality ofelevation data points of an existing surface, storing the plurality ofelevation data points of the existing surface, generating an elevationprofile of the existing surface based on the plurality of elevation datapoints, and determining a surface profile characteristic of travel of anautomobile tire upon the existing surface.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not necessarily restrictive of the invention as claimed. Theaccompanying drawings, which are incorporated in and constitute a partof the specification, illustrate an embodiment of the invention andtogether with the general description, serve to explain the principlesof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The numerous advantages of the present invention may be betterunderstood by those skilled in the art by reference to the accompanyingfigures in which:

FIG. 1 is an isometric view illustrating a smoothness indicator inaccordance with an exemplary embodiment of the present invention;

FIG. 2 is an isometric view of the smoothness indicator illustrated inFIG. 1;

FIG. 3 is a side elevation view of the smoothness indicator illustratedin FIG. 1, wherein a side of the smoothness indicator is illustrated ona paved surface;

FIG. 4 is another side elevation view of the smoothness indicatorillustrated in FIG. 1, wherein the smoothness indicator is illustratedstraddling a paved surface;

FIG. 5 is an isometric view illustrating a smoothness indicator inaccordance with another exemplary embodiment of the present invention,wherein the smoothness indicator is capable of extension and retraction;

FIG. 6 is an isometric view illustrating a smoothness indicator inaccordance with a further exemplary embodiment of the present invention;

FIG. 7 is an end elevation view of the smoothness indicator illustratedin FIG. 6;

FIG. 8 is an isometric view illustrating a slip form paver including asmoothness indicator in accordance with another exemplary embodiment ofthe present invention;

FIG. 9 is a partial isometric view of the slip form paver illustrated inFIG. 8;

FIG. 10 is a partial cross-sectional isometric view of the smoothnessindicator illustrated in FIG. 8, further illustrating an ultrasonicsensor assembly;

FIG. 11 is a partial cross-sectional end elevation view of thesmoothness indicator illustrated in FIG. 8, wherein an ultrasonic sensorassembly includes a temperature gauge assembly;

FIG. 12 is a side elevation view illustrating a sensor assembly for usewith a smoothness indicator in accordance with an exemplary embodimentof the present invention;

FIG. 13 is a side elevation view of the sensor assembly illustrated inFIG. 12, wherein the sensor assembly is shown in operation at an angleθ;

FIG. 14 is a side elevation view of the sensor assembly illustrated inFIG. 12, wherein the sensor assembly is shown in operation at a firstposition P₁ and a second position P₂;

FIG. 15 is a side elevation view illustrating a profile of a roadsurface in accordance with an exemplary embodiment of the presentinvention, wherein the road surface is marked off in a series ofhorizontal increments, and an average elevation between the increments,δ, is shown;

FIG. 16 is an end elevation view illustrating a smoothness indicator inaccordance with a further exemplary embodiment of the present invention,wherein the smoothness indicator includes a series of sensor assembliespositioned over tire track locations on a road surface;

FIG. 17 is a side elevation view illustrating translation of a sensorassembly for use with a smoothness indicator in accordance with anexemplary embodiment of the present invention;

FIG. 18 is a side elevation view illustrating rotation of a sensorassembly for use with a smoothness indicator in accordance with afurther exemplary embodiment of the present invention;

FIG. 19 is a flow diagram illustrating a method for profiling a surfacein accordance with an exemplary embodiment of the present invention;

FIG. 20 is a system diagram illustrating a smoothness indicator inaccordance with another exemplary embodiment of the present invention;

FIG. 21 illustrates a setup screen for a smoothness indicator graphicaluser interface in accordance with an exemplary embodiment of the presentinvention;

FIG. 22 illustrates a job information screen for the smoothnessindicator graphical user interface shown in FIG. 21;

FIG. 23 illustrates two real time traces of a measured surface profilefor the smoothness indicator graphical user interface shown in FIG. 21;

FIG. 24 illustrates a single trace of the measured surface profile forthe smoothness indicator graphical user interface shown in FIG. 21,wherein a user of the smoothness indicator may view the single trace ata specified location;

FIG. 25 illustrates two traces of the measured surface profile for thesmoothness indicator graphical user interface shown in FIG. 21, whereinthe user may view the traces at a specified location;

FIG. 26 illustrates a measurement options screen for the smoothnessindicator graphical user interface shown in FIG. 21;

FIG. 27 illustrates a bump alarm options screen for the smoothnessindicator graphical user interface shown in FIG. 21;

FIG. 28 illustrates a Profile Index report screen for the smoothnessindicator graphical user interface shown in FIG. 21;

FIG. 29 illustrates an International Roughness Index report screen forthe smoothness indicator graphical user interface shown in FIG. 21;

FIG. 30 is an isometric view illustrating a smoothness indicatorincluding a bridge rig having a cantilevered arm in accordance with anexemplary embodiment of the present invention;

FIG. 31 is an isometric view illustrating a smoothness indicatorincluding an all terrain vehicle (ATV) having a cantilevered arm inaccordance with an exemplary embodiment of the present invention;

FIG. 32 is a block diagram of a smoothness indicator analysis systemincluding a smoothness indicator and an information handling system inaccordance with an exemplary embodiment of the present invention;

FIG. 33 is an illustration of a main graphic user interface of theinformation handling system shown in FIG. 32;

FIG. 34 illustrates an exemplary report screen for the main graphic userinterface shown in FIG. 33;

FIG. 35 illustrates an exemplary graph screen displaying two subgradetraces for the exemplary report screen shown in FIG. 34;

FIG. 36 illustrates another exemplary report screen having maximum highand maximum low values of required specifications for the main graphicuser interface shown in FIG. 33;

FIG. 37 is an illustration of a further example of a main graphic userinterface of the information handling system shown in FIG. 32;

FIG. 38 illustrates an exemplary report screen for the main graphic userinterface shown in FIG. 37;

FIG. 39 is a top plan view illustrating a telescoping averaging skiassembly; and

FIG. 40 is a side elevation view of the telescoping averaging skiassembly illustrated in FIG. 39, further illustrating dimensions forsimulating a rolling string line reference trace, in accordance withanother exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the presently preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

Referring generally to FIGS. 1 through 40, a smoothness indicatoranalysis system in accordance with exemplary embodiments of the presentinvention is described. A smoothness indicator 10 may be used formeasuring a profile of a paved surface such as concrete; a base courseincluding cement treated base (CTB), lean concrete base, crushed stone,asphalt, and crushed slag; a subbase, such as subgrade soil oraggregate; a subgrade upon which a subbase, a base, a base course, orpavement is constructed; and other graded surfaces including sand, rock,and gravel. The smoothness indicator 10 may also be used for measuring aprofile of a surface which has not been graded.

The smoothness indicator 10 includes one or more sensor assemblies eachhaving two elevation distance sensors. In exemplary embodiments of thepresent invention, the elevation distance sensors comprise non-contactsensors, such as ultrasonic sensors, laser sensors, or the like. In thismanner, the smoothness indicator 10 may be used to measure profiles forsurfaces which have not cured, such as freshly paved concrete in aplastic state. Each non-contact elevation distance sensor has afootprint over which a distance measurement is taken. In this manner,measurements taken by a non-contact elevation distance sensor reflect aportion of the surface included within the bounds of the sensor'sfootprint. This may have a smoothing/averaging effect for providing amore characteristic representation of the surface. Preferably, thefootprint of a non-contact elevation distance sensor is of sufficientdiameter for smoothing the effect of measurement of minor imperfectionsin the paved road surface, such as texture on the surface (e.g. skidsurface texture), cracks, seams, pebbles, and the like, which may bedisposed upon the road surface. Further, in exemplary embodiments, thefootprint of a non-contact elevation distance sensor approximates thefootprint of a typical automobile tire (i.e. the surface space occupiedby the tire), for providing a surface profile characteristic of travelof the automobile tire upon the surface. In the exemplary embodimentillustrated, for example, each non-contact elevation distance sensor hasa circular footprint with approximately a 6-inch diameter. However, itwill be appreciated that sensors may provide footprints of greater orsmaller diameters without departing from the scope of the presentinvention. Those of skill in the art will appreciate that varioussurfaces may be profiled by the smoothness indicator 10 of the presentinvention. Additionally, while two elevation distance sensors are shownin the accompanying figures, those of skill in the art will appreciatethat more than two elevation distance sensors may also be utilizedwithout departing from the scope of the present invention.

Preferably an independent vehicle or rig is utilized for increasedversatility. For instance, when a road is paved in concrete using a slipform paving machine or the like, a contractor may be graded on meetingsmoothness requirements for the road surface. Utilizing an independentrig including the smoothness indicator of the present invention, thesmoothness of the road may be determined as the road is paved. Forexample, the rig may be driven along behind the paver, while thesmoothness indicator generates a surface profile of the freshly pavedroad. When a surface irregularity, such as a must-grind bump or a lowspot, is encountered, personnel are alerted and work to correct theirregularity, such as utilizing a bull float, a troweling machine, aroller, or the like, while the concrete is still in a plastic state.Then, the rig may be driven over the area of the irregularity to verifythat the corrected road surface meets smoothness requirements.Additionally, the smoothness indicator may be used to gauge theeffectiveness of paving machine settings. In a further example, a paveris connected to the smoothness indicator via a wireless connection forproviding smoothness data to the paving machine supervisor/operator orfor making automatic updates/changes to the paver.

Referring to FIGS. 1 through 7, a smoothness indicator 10 in accordancewith an exemplary embodiment is described. Preferably, the smoothnessindicator 10 includes an extensible and retractable bridge rig assembly12 having one or more sensor assemblies 100. For example, the bridge rig12 may be extended over a four-lane road and retracted for a two-laneroad. The sensor assemblies 100 are positioned for measuring locationsupon a road surface 150, such as where automobile tires travel upon theroad. In a first embodiment, the sensor assemblies 100 may be manuallypositioned, and a setscrew may be provided for locking a sensor assembly100 in place. Alternatively, a drive assembly may be utilized forautomatically adjusting the sensor assembly 100 to a pre-selectedposition.

In the present example, the bridge rig 12 includes a height adjustmentassembly 14, such as an assembly including a hydraulic piston, amechanical linkage, or the like, for adjusting the height of the bridgerig and positioning a sensor assembly 100 a distance from the roadsurface 150. This may be desirable for maintaining the sensor assemblyin an optimal range while profiling the surface. For example, anoperator may wish to maintain a sensor assembly 100 a distance between18 and 24 inches from the road surface 150. It is contemplated that theoperator may position the bridge rig 12 at a median height (the medianheight being relative to the distance between a sensor assembly and theroad surface), such as to account for a banked turn. In furtherembodiments, the smoothness indicator 10 transmits a command to theheight adjustment assembly 14 to position a sensor assembly 100 at aspecified distance from the road surface 150. For instance, the operatormay specify a distance at which the sensor assembly should be locatedfrom the road surface. The smoothness indicator may then transmit acommand to the height adjustment assembly. Those of skill in the artwill appreciate that the command to the height adjustment assembly 14may be transmitted electronically, mechanically, or the like withoutdeparting from the scope of the present invention.

The bridge rig assembly 12 includes at least one travel distance sensor710 connected to a wheel 16 of the bridge rig. The travel distancesensor 710 measures distances traveled by the wheel of the rig todetermine distances traveled by a sensor assembly 100. In embodiments,two or more travel distance sensors are included for determiningdistances over non-linear terrain, such as distances around a sweepinghighway curve. For instance, in the embodiment illustrated, two encodersand/or two pulse pickups may be utilized to measure longitudinaldistances traveled by two wheels of the bridge rig assembly 12 (oneencoder and/or one pulse pickup for each wheel). For example, if firstand second travel distance sensors 710 are included with wheels 16 onboth sides of the bridge rig 12, a weighted average of distancemeasurements from the travel distance sensors may be utilized tocalculate a distance traveled by a sensor assembly between them. Forinstance, an average distance may be used for a sensor assembly 100located in the center of the bridge rig 12. Alternatively, a distancetraveled by a sensor assembly one-fourth a distance from the firsttravel distance sensor to the second travel distance sensor may becalculated by taking 25 percent of a distance measured by the firsttravel distance sensor and adding 75 percent of a distance measured bythe second travel distance sensor. In a further example, a distancemeasuring wheel may be included with the smoothness indicator 10 fordetermining distances traveled by a sensor assembly 100.

In further embodiments, the smoothness indicator 10 includes one or morecontact sensors 18. A contact 20 is included for measuring a distancebetween the bridge rig 12 and a guide, such as a string line positionedfor guiding a paver, or the like. For example, a contact sensor 18 mayfollow a string line 22 for automatically directing the bridge rig 12when measuring a surface profile. The contact 20 follows the string lineas the bridge rig advances over the road surface 150. By analyzingmovement of the contact 20, the smoothness indicator positions thebridge rig 12 for travel in a direction following the direction of theroad. In another embodiment, an elevation distance sensor assembly isutilized to guide the bridge rig by tracking a line, which may be ropeor another type of line detectable by the elevation distance sensor.

A feedback and actuator assembly may be utilized to control the wheel 16of the bridge rig 12. The feedback and actuator assembly may include afeedback sensor (such as a rotary potentiometer, or the like, forsensing an angle of the wheel 16), an actuator, and/or a controlassembly, for guiding the angle of the wheel 16, controlling itsrotational velocity, and/or directing another characteristic of thewheel's movement. For example, a computer assembly or an integratedcircuit utilizing control logic senses a characteristic of the wheel'smovement via the feedback sensor and guides the wheel 16 via theactuator. The feedback and actuator assembly may be coupled with thecontact sensor 18 (or the elevation distance sensor) for controlling thedirection of travel of the bridge rig 12. Alternatively, the bridge rigand/or the wheel are controlled by a Global Positioning System (GPS)directing the rig. In this manner, the bridge rig 12 may travel apredetermined course.

The smoothness indicator 10 is capable of profiling a surface in eithera forward or a reverse direction. For example, the bridge rig 12 maytravel in a forward direction behind a paver. Upon detection of asurface irregularity, such as a must-grind bump or a low spot, thesmoothness indicator 10 may emit an audible alarm, a visual alarm, orthe like, to notify personnel to correct the irregularity. An operatormay then drive the bridge rig assembly 12 backward and forward over thearea of the surface irregularity, repeatedly (if necessary) measuringthe surface until proper correction and/or minimization of theirregularity has been achieved. Various options may be provided foridentifying surface irregularities, such as parameters for must-grindbump size, and other surface criteria.

In one embodiment, previous elevation measurements for locationsmeasured along the road surface 150 are replaced with more recentelevation measurements for the same locations. For example, elevationsmeasured for locations along the road surface before the bridge rig 12is driven backwards over an area are replaced by elevations measuredwhen the bridge rig assembly is driven forward over the area. This hasthe advantage of reflecting the corrected profile of the road surface150 when measuring is resumed.

The smoothness indicator 10 may be utilized for profiling a variety ofsurfaces. Different intervals may be used for averaging measuredelevations when profiling the surfaces, minimizing the elevationsassociated with a profile. For instance, a two-inch interval may beutilized when measuring a concrete surface, while a one-fourth inchinterval may be utilized for a subgrade. The smaller interval may allowfor the detection of rocks, glass, and the like. In still a furtherembodiment, an averaging ski may be used with the sensor assembly 100for measuring a subgrade. In this instance, two averaging skis may beused with the sensor assembly 100: a leading averaging ski, and atrailing averaging ski. It should be noted that various contacting andnon-contacting sensors may be used with the smoothness indicator 10 ofthe present invention to optimize detection for a particular surfacewithout departing from the scope thereof. An example of the variouscontacting sensors may include a wand sensor, or the like. It is to benoted that there are various vendors who produce wand sensors suitablefor the smoothness indicator 10. For example, wand sensors (e.g.,sensors with part number 1035073) produced by TSD Integrated Controls (ajoint venture of Topcon Positioning Systems, Inc. of Livermore, Calif.and Sauer-Danfoss Inc. of Ames, Iowa) may be suitable as the contactingsensors utilized by the smoothness indicator 10.

In embodiments, the bridge rig assembly 12 includes a seat 24 forsupporting an operator. The seat may be adjustable for allowing theoperator a less obstructed view of the road surface 150 or for purposesof comfort. Additionally, the bridge rig 12 includes a steering wheel 26for manually controlling the position of the bridge rig, such as whendriving the rig to a job-site. (Preferably, the bridge rig is orientedlongitudinally with a road when driving to a job-site, occupying onelane of the road.) The steering wheel 26 may be used to overridedirectional commands, while a lockout feature may be provided forpreventing inadvertent direction changes. Preferably, a graphical userinterface assembly 28 is included for setting parameters, enteringinformation, viewing data, and controlling the smoothness indicator 10.A printer 30 may be provided for generating a hard copy, such as asurface profile measured by the smoothness indicator 10, or relateddata.

In order to generate a surface profile, the smoothness indicator 10utilizes a trailing (first) non-contact elevation distance sensor 110and a leading (second) non-contact elevation distance sensor 115 tomeasure a distance D₁ and a distance D₂ from a road surface 150. Bymeasuring angles of incidence of the sensors 110 and 115, and utilizinga known/pre-selected distance D₃ between the sensors, an elevation for afirst location L₁ may be calculated using an elevation assigned to asecond location L₂. It will be appreciated that the terms trailing/firstand leading/second are used to describe non-contacts sensors 110 and 115in relation to the direction of travel of the smoothness indicator 10.In exemplary embodiments, the bridge rig 12 may travel in twodirections. Thus, a trailing/first non-contact elevation distance sensormay become a leading/second non-contact elevation distance sensor if thedirection of travel is reversed. Alternatively, a leading/secondnon-contact elevation distance sensor may become a trailing/firstnon-contact elevation distance sensor in the same manner. For thefollowing description, let the x axis be oriented in a directionparallel to motor vehicle travel on the road surface.

For the present invention, an elevation profile of the road surface isconstructed using a method called the “Incremental Slope Method” (ISM).ISM constructs a road-surface elevation profile by measuring the slopebetween successive pairs of points, such as locations (x₀, y₀) and (x₁,y₁), (oriented such that a line drawn between these points and the xaxis define a plane) on the road surface, which are separated by a knowndistance. Using an elevation/benchmark assigned to one point, it ispossible to calculate an elevation for the other point asy ₁ =y ₀ +md _(x)

where y₀ and y₁ are the elevations of the points at x₀ and x₁,respectively; m is the slope between points 0 and 1; and d_(x) is theknown horizontal distance between the two points.

By moving the sensors in the x-direction a known distance less thand_(x), the process can be repeated and a surface elevation profileconstructed in desired increments. Thus, a priori knowledge or anestimate of the profile for the road surface in the region,x₀≦x≦x₀+d_(x) is needed. Then, for x₀+d_(x)<x, elevations may becalculated, and the road-surface profile constructed as desired (withintolerances of the sensors and other equipment).

For the following analysis, the following definitions are used (see FIG.13):

-   -   x is the coordinate on the abscissa, lying in a horizontal        orientation longitudinally along a road. This coordinate will        curve with the road, but always lies in a horizontal plane.    -   y is the coordinate used on the ordinate, oriented in the        vertical direction.

Referring now to FIGS. 8 through 18, in a further embodiment, thesmoothness indicator 10 includes a first ultrasonic sensor 110 and asecond ultrasonic sensor 115, separated by a pre-selected distance d130. The first and second ultrasonic sensors 110 and 115 use activeultrasonic ranging for measuring the distance to the surface, e.g. froma sensor to the road surface 150. By comparing distance measurementsobtained by the first and second ultrasonic sensors 110 and 115, anelevation difference between locations on the road surface 150 iscomputed. For instance, by measuring a first distance h₁ from the firstultrasonic sensor 110 to a first location (x₁, y₁) on the road surface150 and a second distance h₂ from the second ultrasonic sensor 115 to asecond location (x₂, y₂) on the road surface 150, an elevationdifference h₃ between the first and second locations is computed.

Those of skill in the art will appreciate that the smoothness indicator10 may not travel a level course, due to uneven terrain, thus causingthe first and second ultrasonic sensors 110 and 115 to assume variousangles of incidence relative to a horizontal plane. Electroniccircuitry, mathematical formulae, or other techniques may be used tocalculate the elevation difference h₃ between the first location (x₁,y₁) and the second location (x₂, y₂), such as by noting the variousangles of the first and second ultrasonic sensors relative to thehorizontal.

The first and second ultrasonic sensors 110 and 115 are oriented along aline having a slope θ from the horizontal. In embodiments, theultrasonic sensors are positioned such that the sensors face the roadsurface substantially perpendicular to the line having slope θ from thehorizontal. This places the first and second ultrasonic sensors 110 and115 at the same angle of incidence relative to the horizontal, namelyslope θ. The elevation difference h₃ between the first location (x₁, y₁)measured by the first ultrasonic sensor 110 and the second location (x₂,y₂) measured by the second ultrasonic sensor 115 relative to the roadsurface 150 is computed using the pre-selected distance d 130, the firstand second distances (h₁ and h₂), and the slope θ. The following formulamay be used to compute the elevation difference h₃ between the first andsecond locations (x₁, y₁) and (x₂, y₂) on the road surface 150 measuredby the ultrasonic sensors:h ₃=(h ₁ −h ₂)cos θ+d sin θ.

In exemplary embodiments of the present invention, the first ultrasonicsensor 110 and the second ultrasonic sensor 115 are connected to a paversuch as a concrete paver; a slip form machine; a form-riding machine; abridge deck machine; a tow paver, such as a tow-type paver, a tow-behindpaver, or a box paver; one or more machines in a paving train, includinga spreader or belt placer, a slip form paver, and a curing and texturingmachine; a canal lining paver; a cold planar; a road reclaimer; a roadtrimmer; as well as other vehicles and machines. The first and secondultrasonic sensors 110 and 115 may be adjustably mounted on a paver foridentifying surface irregularities without disrupting paving operations.Preferably, the ultrasonic sensors are mounted on a separate vehicle,such as a bridge rig assembly, thus allowing for repeated surfaceprofiles and rapid profiling of a subgrade. Those of skill in the artwill appreciate that the sensors may be connected to a variety ofvehicles/machines such as an all terrain vehicle (ATV) (see FIG. 31).

In exemplary embodiments of the present invention, the first ultrasonicsensor 110 and the second ultrasonic sensor 115 are connected to amounting assembly, such as a beam 120. A slope sensor 140 may beconnected to the beam, for measuring the slope θ from the horizontal ofthe line along which the ultrasonic sensors are oriented. The ultrasonicsensors are placed facing the road surface 150, such that they areoriented perpendicular to the beam 120 and have the same angle ofincidence relative to the horizontal, slope θ. In this manner, theelevation difference h₃ between the first and second locations (x₁, y₁)and (x₂, y₂) on the road surface 150 measured by the ultrasonic sensorsis computed as described above. Those of skill in the art willappreciate that the first and second ultrasonic sensors 110 and 115 mayeach have a separate slope sensor and/or utilize various sensors fordetermining an angle of incidence relative to the horizontal, to accountfor uneven terrain or the like. Electronic circuitry, mathematicalformulae, and techniques may be used to calculate an elevationdifference between the first and second locations measured by theultrasonic sensors using the various angles of incidence.

In a present embodiment, the slope sensor 140 includes a fluid chamberhaving a gas bubble. By determining a position of the gas bubble withrespect to the chamber at a given instant, the slope θ may bedetermined. However, when a jarring bump is encountered by thesmoothness indicator 10, the gas bubble's position may fluctuate andthus not accurately reflect the slope of the beam 120. In embodiments,the rate of change in the position of the gas bubble is measured (for atime period) to ascertain whether the slope determined is accurate.

For example, measurements obtained during a bump may instead utilize aslope determined before or after the bump. In another example,intermediate slope measurements are calculated over the time interval ofthe bump from slope measurements obtained before and after the bump.These measurements are utilized to calculate intermediate slopemeasurements, such as by interpolating the various slope measurements.In this manner, slope measurements may more accurately reflect the slopeof the beam 120 at a given instant. Other techniques may be used toaccount for jarring, such as the use of an accelerometer coupled withthe beam 120, or the like, for rapidly measuring beam movement.

In one embodiment, the beam 120 connecting the ultrasonic sensors isaffixed/secured to a vehicle, which travels over a surface from a firstposition P₁ to a second position P₂. In another embodiment, the beam 120is longitudinally positioned by the vehicle between the first and secondpositions. For instance, the beam 120 is mounted to a vehicle such thatit is translatable from the first position to the second positionrelative to the vehicle. By using a first elevation difference between afirst pair of locations (x₁ ^(n−1), y₁ ^(n−1)) and (x₂ ^(n−1), y₂^(n−1)), measured by the first and second ultrasonic sensors 110 and 115at the first position P₁, and a second elevation difference between asecond pair of locations (x₁ ^(n), y₁ ^(n)) and (x₂ ^(n), y₂ ^(n)),measured by the first and second ultrasonic sensors 110 and 115 at thesecond position P₂, a profile of the surface is generated throughsuccessive measurements n−1 and n. In this manner, the beam 120 may bemoved from the first position to the second position for measuring theprofile of the surface.

The incremental slope method is used to construct a surface profile bymeasuring the slope between successive pairs of points on the surface(e.g. road surface 150) which are separated by a calculable increment.FIG. 12 provides a schematic of the sensor assembly 100, which comprisestwo sets of non-contacting elevation distance sensors 110 and 115 (forexample, Topcon Positioning Systems, Inc. sells a model called “SonicTracker II” 9142-0000) mounted on a beam 120 a fixed distance, d 130apart, along with a slope sensor 140 which measures the slope of thebeam in the direction of travel. (For example, the slope sensor might bea “System Four Plus Slope Sensor” 9150P/9152P from Topcon PositioningSystems, Inc.) The elevation distance sensors may be any non-contactingdetector such as ultrasonic or laser sensors. Elevation distance sensor115 is ahead of elevation distance sensor 110 in a direction of travelthe assembly will travel. The elevation profile of road surface 150 tothe left (as oriented in FIG. 12) of elevation distance sensor 115 wouldbe known (or estimated).

In the present example, the first and second ultrasonic sensors 110 and115 use active ultrasonic ranging for measuring distances to a surface,such as distances from the ultrasonic sensors to the road surface 150.Preferably, the ultrasonic sensors have an operating range of 14 to 55inches, such as to account for a banked curve. However, the first andsecond ultrasonic sensors 110 and 115 are preferably disposed in a rangeof 18 to 24 inches to minimize atmospheric impact and the like. Those ofskill in the art will appreciate that the sensors should be disposed tominimize atmospheric effects while accommodating lateral heightdifferences.

Preferably, the first and second ultrasonic sensors 110 and 115 arepositioned to remain within the desired operating range. An auditorysignal such as an audible alarm, a visual indicator such as a flashinglight, and/or a mechanical flag may be utilized to alert an operator ifa sensor is out of range or nearing a range limit. For instance, variouscombinations of alerts may be utilized to provide differing levels ofwarnings. Additionally, a mechanical actuator or the like may beprovided for maintaining the beam 120 and/or the first and secondultrasonic sensors 110 and 115 in a desired range. In a further example,a mechanical actuator includes a measuring device for determiningtranslational movement of the beam relative to the vertical direction,and adjusts measurements taken by the first and second ultrasonicsensors 110 and 115 accordingly. In another embodiment, verticaltranslation of the beam may be controlled by an elevation distancesensor coupled with the smoothness indicator 10 for measuring the heightof a string line (which typically correlates to a road surface). Thoseof ordinary skill in the art will appreciate that various othertechniques may be used for maintaining the ultrasonic sensors in adesired range.

Preferably, environmental conditions (such as temperature, etc.) aretaken into account during operation. When taking ultrasonic measurementsover hot asphalt, for instance, correction and/or adjustment of the datagathered by the first and second ultrasonic sensors 110 and 115 isrequired to account for temperature variations in hot, localized airthrough which the distance measurements are taken. For example, atemperature gauge assembly 112, a hydrometer, or the like, may be usedto correct measurements to account for the speed of sound through thelocalized air.

Various methods of determining or estimating the speed of sound throughthe air between the first and second ultrasonic sensors 110 and 115, anda surface to be profiled, may be utilized as well. For example,measurements of a known distance may be taken periodically and used tocalibrate the ultrasonic sensor. Alternatively, the smoothness indicator10 may include optional/required settings for inputting conditions, suchas the type of surface being profiled, the ambient air temperature, andthe like. These settings may then be utilized to adjust and/or correctmeasurements taken by the sensors.

After the elevation difference h₃ between a pair of locations (x₁, y₁)and (x₂, y₂) measured by the first and second ultrasonic sensors 110 and115 has been calculated, the elevation difference h₃ may be added to orsubtracted from a known elevation assigned to one or the other of thepair of locations. For example, if a first elevation y₁ has beenassigned to the first location (x₁, y₁) measured by the first ultrasonicsensor 110, the elevation difference h₃ is added to the first elevationy₁ for calculating a second elevation y₂ for the second location (x₂,y₂) measured by the second ultrasonic sensor 115. If a third elevationy₂′ has been assigned to the second location (x₂, y₂) measured by thesecond ultrasonic sensor 115, the elevation difference h₃ is subtractedfrom the third elevation y₂′ for calculating a fourth elevation y₁′ forthe first location (x₁, y₁) measured by the first ultrasonic sensor 110.Thus, by utilizing a known elevation assigned to a location measured byone of the first and second ultrasonic sensors 110 and 115, an elevationfor another location measured by the other sensor is calculated. Thoseof skill in the art will appreciate that the elevations measured and/orcalculated for the pair of locations (x₁, y₁) and (x₂, y₂) measured bythe first and second sensors may be relative to a pre-selected elevation(e.g. a benchmark), related to an absolute elevation, or the like. Forexample, a GPS measurement may be used as a benchmark, or an elevationinput by a user may be assigned to one of the locations (x₁, y₁) and(x₂, y₂).

The elevation of the road surface 150 as determined by the forwardelevation distance sensor 115 is calculated utilizing the knownelevation at the point sensed by rear elevation distance sensor 110. Themethod is carried out by calculating the vertical distance from the roadsurface to the rear end of beam 120, then the distance from the rear endof beam 120 to the forward end, then the vertical distance from theforward end of beam 120 to the road surface sensed by the forward sensor115. The orientation of the sensing apparatus is shown in FIG. 13. Inpractice, the calculation is as follows:y ₂ =y ₁+(h ₁ −h ₂)cos θ+d sin θ

where the subscript 1 is for the rear sensor, and the subscript 2 is forthe forward sensor. The x (horizontal) coordinate for the forward sensoris also required for later reference. This is found by:x ₂ =x ₁+(h ₂ −h ₁)sin θ+d cos θ

The coordinates (x₁, y₁) and (x₂, y₂) are depicted in FIG. 13. However,the instantaneous x coordinate of the rear sensor is not immediatelyknown. This may be calculated according to the equation below:

$x_{1}^{n} = {x_{1}^{n - 1} + {\Delta\; s^{n}{\cos\left\lbrack {\frac{1}{2}\left( {\theta^{n - 1} + \theta^{n}} \right)} \right\rbrack}} - {\left( {h_{1}^{n - 1} + l} \right)\sin\;\theta^{n - 1}} + {\left( {h_{1}^{n} + l} \right)\sin\;\theta^{n}} + {\frac{1}{2}{d\left( {{\cos\;\theta^{n - 1}} - {\cos\;\theta^{n - 1}}} \right)}}}$

where the superscript n−1 refers to the previous location of beam 120,while superscript n is for the present location of beam 120.

The coordinates (x₂, y₂) are recorded, the beam 120 translated anotherincrement, Δs 170, and the process repeated until the end of the surfaceof interest is reached. Interpolation, such as a polynomial spline fitof the data, may be performed to estimate the coordinates of the roadsurface 150 between the measured points. From the data, roughnessindices may be calculated/output. The data may be displayed as a traceor profile.

A result may be calculated, in a fashion analogous to the measurementmade by a twenty five foot, eight wheeled profilograph (see FIG. 15).Using the recorded (x, y) data, nine points three feet apart (forinstance) are selected or calculated by interpolation. An arithmeticaverage is taken of eight of the elevations (y values)—all except theelevation for point 5 (y₅). Then the vertical distance between point 5and the average is taken as the profilograph output for point 5 (at x₅).A continuous profilograph output may be interpolated between discretemeasurement points.

To determine the road surface elevation profile, we begin with a knownor estimated road surface elevation profile throughout an initialincrement, x₀≦x<x₀+d cos θ⁰ where x₀ is an arbitrary startingcoordinate, and d 130 is the beam length, and θ⁰ is the initial angle ofthe beam 120 measured from the horizontal as shown in FIG. 13. Initialangle θ⁰ is as measured by slope sensor 140.

In the present example, the smoothness indicator 10 measures a surfaceprofile by interleaving a series of discrete profiles measured by thesensor assembly 100. For example, at the start of an elevation profile,the first and second ultrasonic sensors 110 and 115 measure an elevationdifference at a first position P₁ relative to the road surface 150. Afirst elevation measurement y₁ ^(n−1) is assigned to the first location(x₁ ^(n−1), y₁ ^(n−1)) on the road surface 150, measured by the firstultrasonic sensor 110 (in this case, the trailing sensor relative to thedirection of travel); and an elevation difference between the firstlocation (x₁ ^(n−1), y₁ ^(n−1)) and the second location (x₂ ^(n−1), y₂^(n−1)) on the road surface, measured by the second ultrasonic sensor115 (in this case, the leading sensor), is added to the first elevationy₁ ^(n−1) to calculate a second elevation measurement y₂ ^(n−1) for thesecond location (x₂ ^(n−1), y₂ ^(n−1)) on the road surface 150. Inembodiments, the first elevation measurement y₁ ^(n−1) assigned to thefirst location (x₁ ^(n−1), y₁ ^(n−1)) measured by the trailing sensor iszero, and it is assumed that the sensor assembly 100 is starting on alevel surface. In other embodiments, the smoothness indicator 10 allowsthe user to enter initial elevation data for the location measured bythe trailing sensor. Additionally, GPS data or the like may be utilizedto assign an elevation to an initial location measured by the trailingsensor.

The sensor assembly 100 is moved in the direction of travel (e.g. fromleft to right with respect to FIGS. 12 and 13) an incremental horizontaldistance less than or equal to d cos θ⁰. This increment is denoted Δs170 as shown in FIG. 14. A travel distance sensor (such as 710, FIG. 1)is utilized to measure the distance traveled by the sensor assembly 100.At this point, rear elevation distance sensor 110 senses the roadsurface 150 at a location for which the elevation is known (or assumed).Forward elevation distance sensor 115 senses the surface 150 at a newlocation—one for which the elevation has not yet been calculated.

In order to generate a profile for a surface, the elevation differencesare correlated to distances between measurement positions. For example,elevation differences are measured by the first and second ultrasonicsensors 110 and 115 between pairs of locations at first and secondpositions P₁ and P₂, along the direction traveled by the sensor assembly100. In order to determine distances between these positions, anelevation distance sensor is used. For instance, a pulse pickup (PPU)embedded in a drive motor is utilized to measure longitudinal distancesbetween the first and second positions P₁ and P₂. Alternatively, aseparate distance wheel may be included for determining distancesbetween the positions. Those of skill in the art will appreciate thatvarious techniques may be used for determining distances between thefirst and second positions P₁ and P₂ as desired.

The first and second ultrasonic sensors 110 and 115 travellongitudinally along a path (e.g. the road) to the second position P₂,for generating the surface profile. Upon reaching the second positionP₂, another set of measurements are obtained. An initial elevationmeasurement y₁ ^(n) is again assigned to a third location (x₁ ^(n), y₁^(n)) on the road surface 150, measured by the first ultrasonic sensor110 at the second position P₂; and an elevation difference between thethird location (x₁ ^(n), y₁ ^(n)) and a fourth location (x₂ ^(n), y₂^(n)) on the road surface, measured by the second ultrasonic sensor 115at the second position P₂, is added to the initial elevation measurementy₁ ^(n), as described above, for determining an elevation measurement y₂^(n) for the fourth location (x₂ ^(n), y₂ ^(n)) on the road surface 150.This process is repeated until the sensor assembly 100 has traveled thepre-selected distance d 130, at which point elevation measurementsassigned to locations measured by the trailing sensor comprise elevationmeasurements made by the leading sensor. In further embodiments, theelevation measurements are averaged over distance intervals, and anaverage elevation measurement for each interval is stored. For example,the elevation measurements are averaged over 2-inch intervals andstored. In this manner, data storage may be minimized. Additionally, theuse of elevation measurements averaged over distance intervals mayprovide a smoothing and filtering effect.

The translating of the sensor assembly 100 may be carried out in severalways, and the present invention is not to be limited to a particularmode of translation. For example, a plurality of sensor assemblies 100are mounted on the rear of a road paving machine. This permitsadjustment of the paving machine as surface variations are detected.Also, variations may be corrected while the concrete is in a plasticstate. Referring to FIG. 16, a dedicated rig is employed. Again, aplurality of sensor assemblies 100 are utilized to provide a profile ofthe road surface, such as the expected lanes traveled by a vehicle'stires.

As discussed, the elevation profile for an initial portion of thesurface may be known, estimated, or assumed, such as by utilizing agenerally flat section, on the interval x₀≦x<x₀+d cos θ⁰.

One of the ways the surface can be obtained in this region is to assumethe surface is flat for a distance equal to the distance between thefirst and second sensors. The difference between the actual elevation ateach point and the assumed surface will reappear as errors in theelevation (y values) on each interval following the initial one. Thereare two options for improving the resulting surface estimate:

-   -   1. Remove the resulting errors with a low-pass filter by passing        the entire elevation profile through a low-pass filter algorithm        with a cutoff wavelength longer than d—thus diminishing the        error.    -   2. Attempt to remove the error by determining a Taylor Series or        Fourier Series most highly correlated to the y(x) values in        every interval of the surface profile.

In additional examples, the initial surface is obtained by laying aknown flat plate having a length greater than d 130 such that it liesunder both elevation distance sensors at the initial location.Deviations from this flat plate are measured.

Obtaining an initial surface elevation profile is depicted in FIG. 17.In this alternative, translation of the sensor assembly occurs over adistance of at least d cos θ⁰ without movement of the vehicle on whichthe assembly is mounted, such as by a mechanical actuator/carriageassembly. In this manner, the angle, θ, is unchanging throughout theprocess. An additional translation sensor (710 of FIG. 1, for instance)to measure the distance traversed must be included in the apparatus. Forthis approach, the required distance of translation would only be ½ dcos θ⁰ because both sensors may be utilized. The coordinates of the rearsensor are calculated as followsx ₁ ^(n) =x ₁ ^(n−1) +Δs ^(n) cos θy ₁ ^(n) =y ^(n−1) +Δs ^(n) sin θ+(h ₁ ^(n) −h ₂ ^(n))cos θ

where Δs is measured by the additional translation sensor. Thesuperscripts are defined as above. The coordinates for the front sensorare given asx ₂ ^(n) =x ₁ ^(n) +d cos θy ₂ ^(n) =y ₁ ^(n)+(h ₁ ^(n) −h ₂ ^(n))cos θ+d sin θ

Finally, the beam 120 can be rotated parallel to a (roughly) verticalplane about its center (the actual point of rotation is arbitrary, butfor the following analysis, the center is the assumed point ofrotation). No translation is to take place during this process. FIG. 18is a depiction of this method. Let 0 be the initial orientation of thebeam, and 1, 2, . . . , n−1, n, . . . , N be successive angles at whichdiscrete measurements are taken.

To determine the rear elevation distance sensor's final location,x ₁ ¹,

relative to its initial locationx ₁ ⁰,

the horizontal distance from the initial location to the beam's center,then back to the final location, is calculated. Referring to FIG. 18 fornomenclature, the location ofx ₁ ¹

is calculated as:

$x_{1}^{1} + x_{1}^{0} - {\left( {h_{1}^{0} + l} \right)\sin\;\theta^{0}} + {\left( {h_{1}^{1} + l} \right)\sin\;\theta^{1}} + {\frac{1}{2}{d\left( {{\cos\;\theta^{0}} - {\cos\;\theta^{1}}} \right)}}$

The corresponding y location,y ₁ ¹,

relative to the initial y location,y ₁ ⁰,

is determined calculating the vertical distance from the initiallocation to the beam's center, then back to the final location, thus:

$y_{1}^{1} = {y_{1}^{0} - {\left( {h_{1}^{0} + l} \right)\sin\;\theta^{0}} + {\left( {h_{1}^{1} + l} \right)\sin\;\theta^{1}} + {\frac{1}{2}{d\left( {{\cos\;\theta^{0}} - {\cos\;\theta^{1}}} \right)}}}$

At the same time, the rear sensor 110 can be measuring the road surfaceas the beam is rotated. The coordinates when θ=θ⁰ are calculated thus:x ₂ ⁰ =x ₁ ⁰+(h ₂ ⁰ −h ₁ ⁰)sin θ⁰ +d cos θ⁰y ₂ ⁰ =y ₁ ⁰+(h ₁ ⁰ −h ₂ ⁰)cos θ⁰ +d sin θ⁰

Then, as the beam is rotated, the coordinates from both sensors arecalculated as:

$\mspace{79mu}{x_{1}^{n} = {x_{1}^{n - 1} + {\left( {h_{1}^{n - 1} + l} \right)\sin\;\theta^{n - 1}} + {\left( {h_{1}^{n} + l} \right)\sin\;\theta^{n}} + {\frac{1}{2}{d\left( {{\cos\;\theta^{n - 1}} - {\cos\;\theta^{n}}} \right)}}}}$     x₂^(n) = x₁^(n) + (h₂^(n) − h₁^(n))sin  θ^(n) + d cos  θ^(n)$y_{1}^{n} = {y_{1}^{n - 1} + {\left( {h_{1}^{n - 1} + l} \right)\cos\;\theta^{n - 1}} + {\left( {h_{1}^{n} + l} \right)\cos\;\theta^{n}} + {\frac{1}{2}{d\left( {{\sin\;\theta^{n - 1}} - {\sin\;\theta^{n}}} \right)}}}$     y₂^(n) = y₁^(n) + (h₁^(n) − h₂^(n))cos  θ^(n) + d sin  θ^(n)

In the foregoing manner, an elevation profile is an interleaved seriesof discrete profiles. For instance, if elevation measurements aredetermined for pairs of locations at two-inch intervals, and theultrasonic sensors are spaced three feet apart, 18 discrete profileswill be generated and interleaved together. Thus, elevation measurementsfor any two locations spaced two inches apart will be independent ofeach other. Those of skill in the art will appreciate that the spacingof the first and second ultrasonic sensors 110 and 115, the distancebetween measurements taken by the sensors, and the number of discreteprofiles generated may vary as desired.

Because the surface profile generated by the smoothness indicator 10 isan interleaved series of discrete profiles, it will be appreciated thatrandom errors introduced in the course of measuring elevationdifferences between series of locations will propagate, accumulating toform errors for the interleaved series of discrete profiles which mayexceed errors for the elevation measurements of a single profile. Thoseof ordinary skill in the art will appreciate that this may generate anerror band for the interleaved series of measurements larger than thatfor a single profile.

In exemplary embodiments, an incremental spatial filter is applied whengenerating a surface profile. For example, a single-pole low-passspatial filter is utilized to generate a filtered profile of the surface(such as a spatial filter utilizing a nine-inch length constant). Forexample, a series of elevation differences are measured by the firstultrasonic sensor 110 and the second ultrasonic sensor 115, and theelevation differences are used to calculate an average elevationmeasurement over an initial two-inch interval. The average elevationmeasurement for the initial two-inch interval is then filtered, such asby comparing it to an elevation measurement for a second two-inchinterval adjacent to the initial interval. In the current example, asurface profile is post-filtered, or filtered upon completion of theprofile's elevation measurements; while in another embodiment, thesurface profile is incrementally filtered, wherein each new elevationmeasurement for the profile is filtered before being stored. Those ofskill in the art will appreciate that other filters may be used toalter, correct, and/or modify elevation measurements, for increasing therelative accuracy of the measurements, without departing from the scopeand intent of the present invention.

Surface profile data measured by the smoothness indicator 10 may be usedfor deriving information about a surface. In exemplary embodiments, thesurface profile data is used to identify a must-grind bump, a bump whichmust be reduced and/or eliminated from the surface (e.g. to meetconstruction specifications). For example, the smoothness indicator 10may use hardware and/or software installed in an information handlingsystem device, such as a portable computer assembly, to identify amust-grind bump. In embodiments, the smoothness indicator 10 includes amechanical assembly for marking or identifying the must-grind bump, suchas by painting a mark at the location of the bump. Other techniques maybe used to identify a must-grind bump as desired. Additionally, othersurface irregularities may be noted, such as low spots.

An advantage of the present system is that a surface irregularity may beindicated and corrected while the road surface 150 is still in a plasticstate. It will be appreciated that a dedicated smoothness indicator 10may be used to identify a surface irregularity, such as a must grindbump; and the bridge rig assembly 12 may be reversed to allow forsmoothing of the road surface 150. Upon smoothing and/or elimination ofthe irregularity, the smoothness indicator 10 may be moved over thefeature to verify that it has been reduced and/or eliminated and toprovide a profile of the corrected segment. This process may be repeatedas required. In exemplary embodiments of the present invention, surfaceprofile data acquired for the surface irregularity before it has beenreduced and/or eliminated is replaced by data from a second pass, athird pass, or another pass over the irregularity. In this manner, datastored by the smoothness indicator reflects the actual surface profileof the road surface 150, such as for a 1/10 mile road segment. However,it is contemplated that initial measurement data for the feature may beretained by the smoothness indicator 10 for measuring the effectivenessof the corrective operation, for personnel training or the like.

In another embodiment, a surface profile is taken of the road surface150, and elevation measurements determined for the surface are stored bythe smoothness indicator, such as by a Random Access Memory (RAM), aRead-Only Memory (ROM), a magnetic diskette, and/or removable media,such as a floppy disk. These elevation measurements may be utilized todetermine must-grind bumps or other surface irregularities uponcompletion of the elevation profile. In combination with station markerdata, which may be stored along with elevation measurements, the storeddata may be retrieved and examined, such as by hardware or software, toidentify must-grind bumps. An operator may identify the bumps viastation marker data, location data, or other data stored as part of thesurface profile, for identifying the location of the surfaceirregularity. Those of skill in the art will appreciate that otherinformation may be determined upon completion of the profile, such aslow spots, Profile Index data, International Roughness Index data,Gomaco Smoothness Indicator Index data, or the like.

The surface profile data is analyzed to provide data in various formats.In embodiments, surface profile measurements are utilized to produce asimulated profilograph output (FIG. 15). For example, a CaliforniaProfilograph output may be generated. Additionally, Profile Index valuesmay be calculated. Measurements may also be utilized to calculateInternational Roughness Index values, which simulate travel of atheoretical “golden car” over the road surface 150. Typically, indexvalues such as Profile Index values and International Roughness Indexvalues are computed for set intervals, such as between station markers.Another advantage of the smoothness indicator 10 of the presentinvention is that it allows for the calculation of index values, such asGomaco Smoothness Indicator Index values, over a user-defined interval,such as an interval of one-tenth of a mile, for instance. Additionally,the user-defined interval may be centered on any point within theprofile. Those of skill in the art will appreciate that surface profilemeasurements may be formatted in a wide variety of ways.

Referring now to FIG. 19, a method 200 for determining an elevationprofile in accordance with an embodiment is described. In step 202, afirst non-contact elevation distance sensor, such as the firstultrasonic sensor 110, measures a first distance to a surface, such asthe distance h₁ to the road surface 150, at a first location, such asthe location (x₁, y₁). In step 204, a second non-contact elevationdistance sensor, such as the second ultrasonic sensor 115, measures asecond distance to the surface, such as the distance h₂ to the roadsurface 150, at a second location, such as the location (x₂, y₂). Instep 206, a first angle of incidence for the first ultrasonic sensor 110relative to a horizontal plane is determined, such as by measuring angleθ using slope sensor 140. Then, in step 208, a second angle of incidencefor the second ultrasonic sensor 115 relative to the horizontal isdetermined (such as by measuring angle θ using slope sensor 140). Instep 210, an elevation difference, such as elevation difference h₃, iscalculated between the first and second locations, using the first andsecond distances and the first and second angles of incidence. Next, instep 212, the first location (x₁, y₁) along the road surface 150 iscalculated using the first distance and the first angle of incidence.Likewise, in step 214, the second location (x₂, y₂) along the roadsurface 150 is calculated using the second distance and the second angleof incidence. Finally, in step 216, the elevation of the second location(x₂, y₂) is calculated using an elevation assigned to the first location(x₁, y₁), for generating an elevation profile of the road surface.

Referring to FIG. 20, a smoothness indicator 250 in accordance with anexemplary embodiment of the present invention is described. Thesmoothness indicator 250 includes a first elevation distance sensor 252,a second elevation distance sensor 254, a slope sensor 256, a traveldistance sensor 258, a feedback and actuator assembly 260 coupled with awheel 262, and a processor 264 coupled with a memory 266, interconnectedin a bus architecture 268. The first and second elevation distancesensors 252 and 254 are non-contact sensors, such as ultrasonic sensors,laser sensors, or the like. In one embodiment, the first and secondelevation distance sensors are ultrasonic sensors, and they communicatemeasurements to the processor forty times per second. The slope sensor256 is for measuring a slope from a horizontal plane of a line alongwhich the ultrasonic sensors 252 and 254 are oriented. The traveldistance sensor 258 is for measuring distances traveled, such asdistances traveled by the wheel 262. The feedback and actuator assembly260 uses control logic for controlling the wheel 262 via an actuatorassembly. The processor 264 uses distance measurements taken by thefirst and second elevation distance sensors 252 and 254, in combinationwith slope measurements taken by the slope sensor 256, to calculateelevation differences between locations on a surface, such as the roadsurface 150 (FIG. 1). Additionally, the processor 264 communicates withthe memory 266, storing and retrieving elevation measurements forcalculating smoothness index values, Profile Index (PI) values,International Roughness Index (IRI) values, and other elevationmeasurements and indices. The processor 264 may also provide input tothe feedback and actuator assembly 260. For example, the processor maybe coupled with a contact sensor or an elevation distance sensor fortracking the location of a string line and moving the smoothnessindicator 250 accordingly. Those of ordinary skill in the art willappreciate that a smoothness indicator may use various componentswithout departing from the scope and intent of the present invention.

Referring generally to FIGS. 21 through 29, a graphical user interface300 for the smoothness indicator 10 is described. The graphical userinterface 300 may be displayed on a portable information handling systemdevice, such as a personal computer, a dedicated processing assembly, oranother similar machine.

Referring to FIG. 21, a sensor and encoder setup screen 302 isdescribed. The sensor and encoder setup screen 302 includesradio/selection buttons 304 for selecting English and/or metric units. Anumber of text entry boxes 306 may be included for allowing an operatorto input the distances of sensor assemblies 100 relative to a wheel ofthe bridge rig assembly 12, such as a wheel 16 (FIG. 1), or the like. Asecond text entry box 308 is provided for entering the position of acontrol line relative to the wheel. A third text entry box 310 isprovided for inputting the distance between wheels of the bridge rigassembly 12. Load and save buttons 312 are also included for recordingand/or recalling information entered in the text boxes 306, 308, and310. Other text entry boxes may be included for recording parameters forthe smoothness indicator 10 and the like.

Referring now to FIG. 22, a job information screen 314 is described inaccordance with an exemplary embodiment of the present invention. Thejob information screen 314 may include text entry boxes 316 for enteringinformation about a particular profile, a particular job for which aprofile is to be generated, and other information as desired.Information entered in the job information screen 314, may be storedand/or recorded with a surface profile to aid identification.

Referring to FIGS. 23 through 25, exemplary trace displays 318 aredescribed. In embodiments, the trace displays 318 allow a user todynamically view surface profile information from one or more elevationprofiles. The trace displays 318 display surface profile data ingraphical form such as by placing the data on a scale or the like.Indicators such as dashed lines may be superimposed on a trace 320, forindicating station markers relative to points on the trace 320. Thetrace displays 318 may include a slider bar 322, forward and reversebuttons, or similar functionality, for allowing an operator of thesmoothness indicator 10 to observe surface profile data as desired. Inthis case, radio/selection buttons 324 are provided for selecting a realtime display of a surface profile or allowing the operator to view thehistory of the surface profile. Other information such as a file name, ajob description, or other identifying information may be included foridentifying a surface profile. Two or more traces 320 may be displayedon the trace displays 318 at one time. For example, a first trace 320may be located above a second trace 320 for comparison purposes.Alternatively, the first trace 320 may be superimposed in front of, orbehind, the second trace 320. The traces 320 may be displayed in variousformats without departing from the scope of the present invention.

Referring now to FIG. 26, a measurement options screen 326 in accordancewith an exemplary embodiment is described. The measurement optionsscreen 326 includes text entry boxes 328 for entering Profile Indexparameters, text entry boxes 330 for entering International RoughnessIndex parameters, text entry boxes 332 for entering bump detectionparameters, and text entry box 334 for entering smoothness indexparameters. The text boxes 328, 330, 332, and 334, may be used to enterrelevant measurement information for calculating Profile Index data,International Roughness Index data, and smoothness index data.Additionally, these text boxes may be used for defining parameters foractivating a bump alarm or another similar indication of a bump. Thoseof skill in the art will appreciate that various other parameters may beincluded on the measurement options screen 326 without departing fromthe scope and intent of the present invention. Load and save buttons 336are also included for recording and/or recalling information entered inthe text boxes 328, 330, 332, and 334.

Referring to FIG. 27, a bump alarms options screen 338 is described inaccordance with exemplary embodiments of the present invention. Checkboxes 340 are provided for allowing an operator of the smoothnessindicator 10 to selectively determine the functionality of analarm/series of alarms. Various options may be provided for differenttypes of alarms. Additionally, options for controlling a marking (e.g. avisual cue such as a paint sprayer) may be included on the bump alarmoptions screen 338.

Referring now to FIG. 28, a Profile Index report screen 342 isdescribed. The Profile Index report screen 342 includes radio/selectionbuttons 344 for allowing an operator of the smoothness indicator 10 toview Profile Index report information 346. The Profile Index reportinformation 346 is calculated by the smoothness indicator 10, anddisplayed according to a radio/selection button 344 selected by theuser. Additionally, text boxes 348 are included for entering parametersfor calculating the Profile Index report information 346. These textboxes 348 may allow entry for information such as minimum scallopheight, minimum scallop width, segment length, scallop resolution,blanking band, and the like. Those of ordinary skill in the art willappreciate that other various parameters for calculating the ProfileIndex report information 346 may be included without departing from thescope and intent of the present invention.

Referring now to FIG. 29, an International Roughness Index report screen350 is described in accordance with exemplary embodiments of the presentinvention. The International Roughness Index report screen 350 includesradio/selection buttons 352 for allowing an operator of the smoothnessindicator 10 to view International Roughness Index report information354. The International Roughness Index report information 354 iscalculated by the smoothness indicator 10, and displayed according to aradio/selection button 352 selected by the user. Additionally, a textbox 356 is included for entering parameters for calculating theInternational Roughness Index report information 354. The text box 356may be provided along with other text boxes for entry of informationsuch as segment length, and the like. Various parameters for calculatingthe International Roughness Index report information 354 may be includedwithout departing from the scope and spirit of the present invention.

Referring to FIGS. 30 and 31, a smoothness indicator 10 including one ormore sensor assemblies 100, like the embodiments illustrated in FIGS. 1through 7, is described in accordance with further exemplaryembodiments. The smoothness indicator 10 includes a bridge rig 12 havinga cantilevered arm 13. The cantilevered arm 13 may be extended over asurface 150 for profiling the surface. For instance, the cantileveredarm may be folded and/or stowed alongside the rig 12 for transport, andextended for profiling a surface. The sensor assemblies 100 arepositioned for measuring locations upon the surface 150, such as whereautomobile tires may travel upon the surface. In a first embodiment, thesensor assemblies 100 may be manually positioned. Alternatively, a driveassembly may be utilized for automatically adjusting a sensor assembly100 to a pre-selected position.

The smoothness indicator 10 may include a height adjustment assembly 14,such as an assembly including a hydraulic piston, a mechanical linkage,or the like, for adjusting the height of the smoothness indicator 10 andpositioning a sensor assembly 100 a distance from the surface 150. Thismay be desirable for maintaining the sensor assembly in an optimal rangewhile profiling the surface. In further embodiments, the smoothnessindicator 10 transmits a command to the height adjustment assembly 14 toposition a sensor assembly 100 at a specified distance from the surface150.

The smoothness indicator 10 may include a travel distance sensor 710connected to a wheel 16 of the smoothness indicator. The travel distancesensor 710 measures distances traveled by the wheel of the smoothnessindicator to determine distances traveled by a sensor assembly 100. Inembodiments, two or more travel distance sensors are included fordetermining distances over non-linear terrain, such as distances arounda sweeping highway curve. In a further example, a distance measuringwheel may be included with the smoothness indicator 10 for determiningdistances traveled by a sensor assembly 100.

In further embodiments, the smoothness indicator 10 includes one or morecontact sensors 18. A contact 20 is included for measuring a distancebetween the smoothness indicator 10 and a guide, such as a string linepositioned for guiding a paver, or the like. For example, a contactsensor 18 may follow a string line 22 for automatically directing thesmoothness indicator 10 when measuring a surface profile. The contact 20follows the string line as the smoothness indicator advances over thesurface 150. By analyzing movement of the contact 20, the smoothnessindicator positions the smoothness indicator 10 for travel in adirection following the direction of the surface. In another embodiment,an elevation distance sensor assembly is utilized to guide thesmoothness indicator by tracking a line, which may be rope or anothertype of line detectable by the elevation distance sensor.

A feedback and actuator assembly may be utilized to control the wheel 16of the smoothness indicator 10. The feedback and actuator assembly mayinclude a feedback sensor (such as a rotary potentiometer, or the like,for sensing an angle of the wheel 16), an actuator, and/or a controlassembly, for guiding the angle of the wheel 16, controlling itsrotational velocity, and/or directing another characteristic of thewheel's movement. The feedback and actuator assembly may be coupled withthe contact sensor 18 (or the elevation distance sensor) for controllingthe direction of travel of the smoothness indicator 10. Alternatively,the smoothness indicator and/or the wheel are controlled by a LocalPositioning System (LPS) (e.g. a robotic total station), a GlobalPositioning System (GPS), or the like, for directing the smoothnessindicator. In this manner, the smoothness indicator 10 may travel apredetermined course.

Referring now to FIG. 31, the surface 150 over which the cantileveredarm 13 is extended may comprise a subgrade. A sensor assembly 100 ispositioned for measuring locations upon the subgrade, such as fordetermining the thickness of pavement to be constructed upon thesubgrade. Thus, the smoothness indicator 10 may be utilized to check thesubgrade. For example, the smoothness indicator may be correlated to aline detected by an elevation distance sensor for determining apercentage yield for a paving material such as concrete or asphalt.Alternatively, the contact sensor 18 may be used to compare the stringline 22 to the subgrade. For instance, string line used by a paver fordetermining the thickness of a paved surface, such as a road surface,may be compared to the subgrade for determining pavement thickness atvarious locations and minimizing surface inconsistencies which reducethe percentage yield. In such a case, the contact sensor 18 may bereplaced by an elevation distance sensor or the like as needed.

Referring generally to FIGS. 32 through 38, the smoothness indicatoranalysis system 320 for analyzing elevation information 330 collectedand measured by a smoothness indicator 10 is described. The smoothnessindicator analysis system 320 generates a comprehensive report and agraphic user interface display useful for planning pavement projects andmaintaining the paved road.

Referring now to FIG. 32, the smoothness indicator analysis systemincludes information handling system 322 comprising display devices 324and generating various reports 326. As discussed, the smoothnessindicator 10 is configured to determine elevation information 321 suchas a surface profile taken of the road surface 150, elevationmeasurements for the surface, string line elevation profile data,subgrade elevation profile data, or the like. The elevation information321 regarding the road surface may be stored by the smoothness indicator10, such as by a Random Access Memory (RAM), a Read-Only Memory (ROM), amagnetic diskette, and/or removable media, such as a floppy disk.

The information handling system 322 may be accessed through a network byvarious users 328. In an embodiment of the present invention, theinformation handling system 322 may provide a web based graphic userinterface for allowing users 328 to select user options and viewanalyzed results.

The elevation information 321 such as elevation measurement data may beutilized to determine a cut or fill surface area or other surfaceirregularities upon completion of the elevation profile. In oneembodiment, the information handling system 322 may be communicativelyconnected to the smoothness indicator 10 through a network. As such, theinformation handling system 322 may receive the elevation information321 from the smoothness indicator 10 via a wireless network connection(e.g. wireless fidelity (Wi-Fi) network connection or the like).Alternatively, the information handling system 322 may upload theelevation information directly from the memory of the smoothnessindicator, such as RAM, ROM, or the like. In an alternative embodiment,the information handling system 322 may be a stand alone system whichmay not be communicatively coupled to the smoothness indictor 10. Theinformation handling system 322 may upload the elevation information 321from a magnetic diskette, removable media, or the like, which has beenpreviously stored by the smoothness indicator.

Referring now to FIG. 33, a main Graphic User Interface (GUI) 330 forthe information handling system of the present invention is described.In an embodiment of the present invention, the main GUI 330 may displaya list 332 of string line elevation profile data and a list 334 ofsubgrade elevation profile data. The user may be allowed to add ordelete elevation profile data from the lists 332, 334 to execute adesired analysis. It is to be noted that elevation profile data forstring lines and elevation profile data for each subgrade trace may becategorized by various factors such as a date/time, a geographiclocation, an individual smoothness indicator, or the like. For example,the user may add elevation profile data collected by a certainsmoothness indicator during day 1 and day 2. Later, the user may deletethe elevation profile data collected during day 1. The selectedelevation profile data may be uploaded to the information handlingsystem 322.

The main GUI 330 may allow a user to enter various input parameters 336,338 to the information handing system. For example, dimensions such aslength, width, and depth of a concrete slab may be entered. The concreteslab may be constructed upon a subgrade. These dimensions may be used tocalculate a design volume (i.e., the theoretical volume of pavingmaterial needed to construct the slab) of an intended surface (i.e., anideal pavement surface) which may be compared to an expected volumecalculated from the elevation measurements for the subgrade and/or thestring line to determine a predicted volume difference. In analternative embodiment, overall average volume change may be estimatedif elevation profiles from multiple sensor assemblies 100 are used. Ifthe predicted volume differences or overall average volume change are tobe excessive, the subgrade may be modified accordingly in order toreduce or eliminate the actual volume difference after paving, savingpaving material and reducing the cost of the slab. Those of skill in theart will appreciate that other data may be calculated by comparingsubgrade and/or string line elevation measurements without departingfrom the scope and intent of the present invention.

The information handling system may compare elevation measurements for asubgrade against various reference elevation points. In one embodiment,three dimensional theoretical elevation data, such as GPS collectedelevation data, may be utilized to determine an intended surface andthus, no string line is used as a reference elevation point. It is to benoted that it is well known to the art that the three dimensionaltheoretical elevation data is collected without any string lines. In analternative embodiment, various reference elevation points such asstring lines, road lines, and the like may be utilized to collectinformation to determine an intended surface of pavement. For example,when the smoothness indicator scans and generates elevation information,a user may choose the number of string lines for elevation profilemeasurements. Thus, two string lines, a single string line, no stringlines, or the like may be used by the smoothness indicator to compareelevation measurements. Such comparison may be, for example, comparingelevation data points of an existing surface (e.g., a subgrade or apavement surface, such as in a plastic state) to elevation data pointsof the intended surface to determine whether a relative elevationdifference exists between the elevation data points of an existingsurface and the elevation data points of the intended surface.

Generally, a string line may be utilized by a paver for determining thethickness of a paved surface to be constructed upon a subgrade. Thus,the information handling system may determine a percentage yield for apaving material such as concrete by comparing elevation measurements forthe subgrade against elevation measurements for the string line. Assuch, the information handling system may analyze the elevation profiledata to determine an amount of paving material required for a givenportion of the road surface based on the user selections and theelevation data. It is further contemplated that the information handlingsystem also estimates the pavement thickness of a given portion of theroad surface. In this manner, the information handling system mayprovide various analyzed results useful for planning the pavement of theroad surface. Preferably, surface inconsistencies, which can reduce thepercentage yield of a paving material, may be identified.

Referring now to FIG. 34, an exemplary report screen 340 for the mainGUI 330 is shown. An elevation profile measured for the subgrade may becompared against an elevation profile measured for a string line.Alternatively, a profile of elevation difference measurements (elevationderivation) may be generated, such as by measuring elevation differencesbetween a subgrade and a string line at various locations. In a stillfurther embodiment, elevation measurements for either of the subgradeand the string line are compared against theoretical elevationmeasurements for the other of the subgrade and the string line. A usermay have a choice to have various reports via a selection menu 342. Thereports may include an Engineering Research Division (ERD) ElevationData report, a Virtual elevation data report, a True profile report, agrade Cut/Fill report, or the like. It is to be noted that the ERD fileformat and ERD software are well known to the art. The ERD file formathas been utilized to facilitate automated plotting of simulation data,experimentally measured data, and data from various analysis programs.Those of ordinary skill in the art will appreciate that the informationhandling system may generate various forms of reports based on itsanalysis. For each report, a corresponding graph image may be displayedwhen the user selects Show Graph menu 344 from the report screen 340.

Referring now to FIG. 35, a graph screen 350 displaying two subgradetraces is shown. In an embodiment of the present invention, the graphscreen 350 may display the analyzed elevation information in graphicalform such as by placing the data on a scale or the like. Preferably,elevation information of two or more subgrade traces may be displayed onthe graph screen 350 at one time. For example, first trace elevationprofile 352 may be located above second trace elevation profile 353 forcomparison purposes. Additionally, the user may choose to view a graphof each trace's true profile (grade removed) data, or a graph of eachtrace's string line deviation, or the like.

In one embodiment, surface profile data measured by the smoothnessindicator may be used for deriving information about a surface. Theinformation handling system may analyze the surface profile data to aidusers in finding subgrade to be cut or filled. For example, high areasmay be a must-grind bump, a bump which must be reduced and/or eliminatedfrom the surface (e.g. to meet construction specifications). Low areamay be an area which must be filled. The information handling system maydisplay a table showing such information to identify irregularity of thesubgrade.

Referring now to FIG. 36, a table screen 360 having maximum high andmaximum low values for required specifications is shown. In a furtherembodiment, the main GUI 330 allows the user to set the maximum high andmaximum low values and corresponding colors for the requiredspecifications. In an embodiment, the maximum high and maximum lowvalues are measured with respect to expected values, calculatedutilizing information related to the expected grade of the surface to bepaved. In other embodiments, the maximum high and maximum low values maybe identified utilizing other information, including information aboutan actual subgrade and a theoretical subgrade or the like. For example,the user may select the upper limit to show in green for anyspecification which is −0.25 or higher. A user may select the lowerlimit to show in red for any specification which is −2.0 or below. Insuch a case, the table 360 may display the required specifications indifferent colors 362, 364 in order to help the user to recognizepotential problems of the road surface. Alternatively, other graphicalmethods such as highlighting, flashing, shading, or the like may beutilized to display the required specifications.

It is noted that the surface profile data may be analyzed to providevarious reports and displays in various formats. In one embodiment,surface profile measurements are utilized to produce index values suchas Profile Index values and International Roughness Index values whichare computed for set intervals, such as between station markers.Additionally, the user-defined interval may be centered on any pointwithin the profile. The main GUI 330 may also allow the user to input awidth of string lines, a maximum high and a maximum low of anirregularity of the subgrade, the number of subgrade traces used, or thelike.

Referring now to FIG. 37, another exemplary main Graphic User Interface(GUI) 370 for the information handling system of the present inventionis described. In an embodiment of the present invention, the main GUI370 may display a list of string line elevation profile data and a listof wheel path trace elevation profile data. The user may be allowed toadd or delete elevation profile data from the lists to execute a desiredanalysis. The main GUI 370 may allow a user to enter various inputparameters such as a slab definition, Grade Cut/Fill parameters, Sensorpositions, Grade offsets, and the like. The user may select variousviews of the analyzed information. For example, the user may select atable view 376 to have an elevation data table view, a true profile datatable view, a Grade cut/fill details table view, a Grade Cut/fillsummary table view, and the like. Additionally, the user may choose tohave a graph view 378 of elevation data, true profile, Grade cut/filldetails or the like. When the user selects an analysis report 379 fromthe main graphic user interface, a comprehensive grade analysis reportmay be provided so that the user can print the comprehensive gradeanalysis report, transfer the comprehensive grade analysis reportelectronically (e.g. via an e-mail or the like), or view thecomprehensive grade analysis report through the main GUI 370.

In a further embodiment, the information handling system may provide asimulated paver mold pan line. When the user chooses to use two stringline traces for the smoothness indicator, the information handlingsystem may create a line (a simulated paver mold pan line) to replicatewhat the paver mold will be located on a paved road. Advantageously, thesimulated paver mold pan line may be utilized as a base line forpavement of a road.

Typically, two string lines are not exactly parallel with each otherwhile the elevation information is collected by the smoothnessindicator. Thus, in order to get accurate elevation information, it isimportant to have trace information regarding locations of the traces inreference to each string line. After finding the true elevation (graderemoved) by the smoothness indicator, the information handling systemmay determine trace information regarding the locations of traces inreference to each string line or the simulated paver mold pan line.

Y_(p), which is a slope between the first string line and the secondstring line at incremental point (j), is calculated as follows:

$Y_{p} = \frac{\left( {{{SL}\; 1(j)} - {{SL}\; 0(j)}} \right)}{Ws}$

where SL0(j) is a height of the first string line at incremental point(j), SL1(j) is a height of the second string line at incremental point(j), and Ws is a width between the first string line and the secondstring line.

Y_(t), which is the height of a sensor in reference to the first stringline at incremental point (j), is calculated as follows:Y _(t) =Y _(p)*SensorPosition+SL0(j)

Tr1(j), the actual deviation of a second trace at incremental point (j),is calculated for the deviation of a wheel path as follows:Tr1(j)=−1*(Y _(t) −WP(j))

where WP(j) is a wheel path at incremental point (j).

If the start point and/or the end point has an inaccurate grade cut, theprofile value is calculated as follows:ProfileValue=WP(j)−((j*WP.avgSlope)+(OffsetSlopeDiff*(ndata−1)−j)+(EndOffsetSlopeDiff*j))

where WP.avgSlope is an average slope of the Wheel Path, OffsetSlopeDiffis an offset of the start point, and EndOffsetSlopeDiff is an offset ofthe end point. Ndata is a total number of data points taken by thesmoothness indicator. After the value of ProfileValue is calculated, theinformation handling system may compare the actual deviation of thefirst trace to the first string line to determine the deviation from thesimulated paver mold pan line. In this manner, trace informationregarding locations of the traces in reference to each string line or asimulated paver mold pan line may be determined.

Tr0(j), the actual deviation of a first trace at incremental point (j),is calculated as follows:Tr0(j)=(Y _(p))*(Wtr0(j))+S0(j)

where Wtr0(j) is a width of the first trace to the first string line atincremental point (j) and S0(j) is a raw value for the first string lineat incremental point (j).

If an offset for the first trace is needed to correct for an inaccurategrade cut at the beginning of a job, Tr0(j) is calculated as follows:Tr0(j)=j*(Echg/Range)+(Offset/Range)*(Range−j)

where (j) is an incremental point at which elevation data was taken,Offset is the offset value for the first trace, Range is a range ofincremental points, and Echg is an elevation change increment value.After the value of Tr0(j) is calculated, the information handling systemmay compare the actual deviation of the first trace at incremental point(j) to S0(j) to determine the deviation from the simulated paver moldpan line. In this manner, trace information regarding locations of thetraces in reference to each string line or a simulated paver mold panline may be determined.

It is contemplated that the information handling system, communicativelycoupled to a smoothness indicator, may simulate the paver mold pan lineto the theoretic pave pan movement while the surface of the road isbeing paved.

It is further contemplated that the information handling system,communicatively coupled to a smoothness indicator, may provide a realtime pavement thickness which will aid users to calculate elevationchanges of the sub-grade, sub-base, or the like as it may be beforepaving (either seconds, hours, or days before paving) or at anytimeduring the pavement process. Additionally, the information handlingsystem may aid users in calculating the elevation changes for the finalsurface of the pavement. Further, the information handling system mayplace a distance stamp on each elevation value.

In an embodiment of the present invention, first profile information maybe gathered by a first smoothness indicator in front of the paver andsecond profile information may be gathered by a second smoothnessindicator right behind the paver. The first profile information and thesecond profile information may be uploaded by the information handlingsystem in a real time manner. Preferably, the information handlingsystem may be communicatively coupled to the smoothness indicators viaconventional wireless network connections such as a WI-FI connection, orthe like. It should be noted that the wireless network communication canbe implemented in various ways. Further, it is also to be noted thatadditional information may be needed by the information handling systemto determine the real-time thickness. The information system may meshthe first and the second profile information together to see thereal-time thickness. The first and the second profile information may beoverlaid in graphical form such as by placing the data on a scale, orthe like, to show the elevation difference at a given portion of thesurface. In this manner, the user may be able to have real-timeassessment and analysis of the pavement thickness.

In a further embodiment of the present invention, the informationhandling system may be useful for a user for inspecting pavement of theroad. Typically, a DOT inspector may have to lay on the back of thepaver and use a dip stick in random places to check thickness todetermine whether the thickness is within specification or not. Thepresent invention may aid the user, such as a DOT inspector, by allowingfor time thinness information, releasing the user from tedious and timeconsuming inspection.

Referring now to FIGS. 39 and 40, for the following analysis, let Sequal an array of values measured by an elevation distance sensor, suchas the first non-contact elevation distance sensor 110, the secondnon-contact elevation distance sensor 115, an ultrasonic sensor, a lasersensor, or the like. If an individual value, S_(i), of array S is out oferror tolerance, then that value may be replaced with another valueinterpolated as follows:

$S_{i} = {\left( {\frac{{{S_{x} \cdot {Station}} - {S_{i} \cdot {Station}}}}{{{S_{x} \cdot {Station}} - {S_{y} \cdot {Station}}}}*\left( {S_{y} - S_{x}} \right)} \right) + S_{x}}$

where S is the array of values measured by the elevation distancesensor, i is the current index of S, x is the index of the previous goodvalue of S, and y is the index of the next good value of S.

The average of a group of values taken before and after an individualvalue, S_(i), of array S is calculated as follows:S _(i)=((Σ_(j=i−1) ^(i−AvgLen) S _(j))+(Σ_(j=i+1) ^(i+AvgLen) S_(j)))_(avg)

where S is the array of values measured by the elevation distancesensor, i is the current index of S, and AvgLen is the number of valuesbefore and after i to average.

An individual value, S_(i), of array S may be “zeroed” (i.e., adjustedwith reference to an initial point or origin) as follows:S _(i)=(S _(i) −S ₀)

where S is the array of values measured by the elevation distancesensor, i is the current index of S, and S₀ is a value representing aninitial point or origin.

A value for simulating a rolling string line reference trace (e.g., avalue representing a theoretical measurement taken by the telescopingaveraging ski assembly illustrated in FIGS. 39 and 40) may be calculatedas follows:

$S_{i} = {{\frac{\left( {S_{f\; 1} + S_{f\; 2} + S_{f\; 3} + S_{f\; 4}} \right)_{avg} - \left( {S_{b\; 1} + S_{b\; 2} + S_{b\; 3} + S_{b\; 4}} \right)_{avg}}{StringLineDist}*\left( {{StringLineDist} - {ReferenceDist}} \right)} + \left( {S_{b\; 1} + S_{b\; 2} + S_{b\; 3} + S_{b\; 4}} \right)_{avg}}$

where S is the array of values measured by the elevation distancesensor; i is the current index of S; and b1, b2, b3, b4, f1, f2, f3, andf4 are indices selected from S. Indices b1, b2, b3, b4, f1, f2, f3, andf4 are calculated as follows:

${b\; 1} = {i - \frac{{feetBeforeAvg}*12.0}{2.0}}$${b\; 2} = {{b\; 1} + \frac{BogieTrolleyWidth}{2.0}}$${b\; 3} = {i - \frac{{feetToBackWheel}\; 3*12.0}{2.0}}$${b\; 4} = {{b\; 3} + \frac{BogieTrolleyWidth}{2.0}}$${f\; 1} = {i + \frac{{feetToFrontWheel}\; 1*12.0}{2.0}}$${f\; 2} = {{f\; 1} + \frac{BogieTrolleyWidth}{2.0}}$${f\; 3} = {i + \frac{{feetToFrontWheel}\; 3*12.0}{2.0}}$${f\; 4} = {{f\; 3} + \frac{BogieTrolleyWidth}{2.0}}$

where feetBeforeAvg, feetToBackWheel3, feetToFrontWheel1, andfeetToFrontWheel3 are calculated as follows:feetBeforeAvg=StringLineDist−ReferenceDist+(BogieCouplerWidth/2.0/12.0)+(BogieTrolleyWidth/2.0/12.0)feetToBackWheel3=StringLineDist−ReferenceDist−(BogieCouplerWidth/2.0/12.0)+(BogieTrolleyWidth/2.0/12.0)feetToFrontWheel1=ReferenceDist−(BogieCouplerWidth/2.0/12.0)−(BogieTrolleyWidth/2.0/12.0)feetToFrontWheel3=ReferenceDist+(BogieCouplerWidth/2.0/12.0)−(BogieTrolleyWidth/2.0/12.0)

An individual value, S_(i), of array S may be interpolated for stationline up as follows:

$S_{i} = {\left( {\frac{{{S_{x} \cdot {Station}} - {R_{i} \cdot {Station}}}}{{{S_{x} \cdot {Station}} - {S_{y} \cdot {Station}}}}*\left( {S_{y} - S_{x}} \right)} \right) + S_{x}}$

where S is the array of values measured by the elevation distancesensor, i is the current index of S, R is an array of reference tracevalues, x is the starting index where S_(x).Station≦R_(i).Station, and yis the ending index where S_(y).Station≧R_(i).Station.

Let D equal an array of values representing individual deviations ofelements of array S from a reference line. An individual value, D_(j),of array D may be calculated as follows:

$D_{j} = {\left( {\left( {\frac{{R\; 1_{j}} - {R\; 0_{j}}}{refineWidth} + {SP}_{i} + {RO}_{j}} \right) - S_{j}} \right) + O_{i}}$

where S is the array of values measured by the elevation distancesensor, i is the trace index of S, j is the current index of D, R0 is afirst reference trace, R1 is a second reference trace, SP is a sensorposition, O is an array of sensor elevation offsets, and reflineWidth isthe distance between reference traces R0 and R1.

The volume V of a slab may be calculated as follows:

$V = \left( {\left( {{\sum\limits_{i = 0}^{n}{{len}*\left( {{SP}_{0} - \frac{{reflineWidth} - {slabWidth}}{2}} \right)*{{WP}\lbrack 0\rbrack}_{i}}} + {\left. \quad{{{WP}\lbrack 0\rbrack}_{i + 1} + {{WP}\lbrack 0\rbrack}_{i} + {{WP}\lbrack 0\rbrack}_{i + 1}} \right)_{avg}*{- 1}}} \right) + \left( {\sum\limits_{i = 0}^{n}\left( {\sum\limits_{j = 0}^{t - 1}{{len}*\left( {{SP}_{j + 1} - {SP}_{j}} \right)*\left( {{{WP}\lbrack j\rbrack}_{i} + {{WP}\lbrack j\rbrack}_{i + 1} + {{WP}\left\lbrack {j + 1} \right\rbrack}_{i} + {{WP}\left\lbrack {j + 1} \right\rbrack}_{i + 1}} \right)_{avg}*{- 1}}} \right)} \right) + \left( {\sum\limits_{i = 0}^{n}{{len}*\left( {{reflineWidth} - {SP}_{t - 1} - \frac{{reflineWidth} - {slabWidth}}{2}} \right)*\left( {{{WP}\left\lbrack {t - 1} \right\rbrack}_{i} + {{WP}\left\lbrack {t - 1} \right\rbrack}_{i + 1} + {{WP}\left\lbrack {t - 1} \right\rbrack}_{i} + {\left. \quad{{WP}\left\lbrack {t - 1} \right\rbrack}_{i + 1} \right)_{avg}*{- 1}}} \right)}} \right)} \right.$

where len is the distance between trace points, reflineWidth is thedistance between reference traces, slabWidth is the width of the slab, tis the number of traces, SP is an array of sensor positions, and WP isan array of sensor path traces.

It is believed that the present invention and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, constructionand arrangement of the components thereof without departing from thescope and spirit of the invention or without sacrificing all of itsmaterial advantages. The form herein before described being merely anexplanatory embodiment thereof, it is the intention of the followingclaims to encompass and include such changes.

What is claimed is:
 1. A method for analyzing roadway information,comprising: receiving a first set of elevation data points defining atleast a portion of an existing surface; receiving a second set ofelevation data points defining at least a portion of an intendedsurface, the intended surface is configured as an exterior concretesurface prior to pavement, the exterior concrete surface is configuredfor travel upon by a motorized vehicle; receiving at least one angle ofincidence corresponding to the first set of elevation data points;adjusting the first set of elevation data points based on the at leastone angle of incidence to ensure that the first set of elevation datapoints and second set of elevation data points correspond tosubstantially parallel planes; comparing, via a computer processingdevice, the first set of elevation data points to the second set ofelevation data points to determine whether an elevation differenceexists between corresponding data points of the first set of elevationdata points and the second set of elevation data points, where a datapoint of the first set of elevation data points is a corresponding datapoint to a data point of the second set of elevation data points whenthe data point of the first set of elevation data points and the datapoint of the second set of elevation data points has a same x and ycoordinate of a horizontal plane; storing a comparison of the first setof elevation data points to the second set of elevation data points whenit is determined that an elevation difference exists betweencorresponding data points of the first set of elevation data points andthe second set of elevation data points; and generating an automatedreport displaying the comparison, the report defining a high spot or alow spot on the existing surface when an elevation difference existsbetween corresponding data points of the first set of elevation datapoints and the second set of elevation data points.
 2. The method ofclaim 1, wherein the existing surface includes at least one of asubgrade or a concrete pavement surface in a plastic state.
 3. Themethod of claim 1, further comprising: deriving the intended surface atleast in part from at least one of a string line elevation profile orthree dimensional theoretical elevation data.
 4. The method of claim 1,wherein the existing surface is a subgrade.
 5. The method of claim 4,further comprising: deriving the intended surface at least in part fromat least one of a string line elevation profile or three dimensionaltheoretical elevation data, wherein the report indicates a surfaceirregularity in the subgrade to be corrected prior to introducing apaving material to the subgrade.
 6. The method of claim 4, furtherincluding: receiving a user input regarding at least one of a length, awidth, or a depth of a pavement portion to form onto the subgrade. 7.The method of claim 6, further including: calculating a design volume ofthe pavement portion; and determining a predicted volume differencebetween the design volume and a volume between the subgrade and theintended surface.
 8. The method of claim 1, wherein receiving a firstset of elevation data points defining at least a portion of an existingsurface includes: establishing a communicative connection with a sourceof the first set of elevation data points to receive the first set ofelevation data points.
 9. The method of claim 8, wherein thecommunicative connection includes a wireless network connection.
 10. Themethod of claim 1, wherein receiving a first set of elevation datapoints includes: uploading a first set of elevation data points from amemory of a source of the first set of elevation data points.
 11. Aapparatus for analyzing roadway information, comprising: means forreceiving a first set of elevation data points defining at least aportion of an existing surface; means for receiving a second set ofelevation data points defining at least a portion of an intendedsurface, the intended surface is configured as an exterior concretesurface prior to pavement, the exterior concrete surface is configuredfor travel upon by a motorized vehicle; means for receiving at least oneangle of incidence corresponding to the first set of elevation datapoints; means for adjusting the first set of elevation data points basedon the at least one angle of incidence to ensure that the first set ofelevation data points and second set of elevation data points correspondto substantially parallel planes; means for comparing the first set ofelevation data points to the second set of elevation data points todetermine whether an elevation difference exists between correspondingdata points of the first set of elevation data points and the second setof elevation data points, where a data point of the first set ofelevation data points is a corresponding data point to a data point ofthe second set of elevation data points when the data point of the firstset of elevation data points and the data point of the second set ofelevation data points has a same x and y coordinate of a horizontalplane; means for storing a comparison of the first set of elevation datapoints to the second set of elevation data points when it is determinedthat an elevation difference exists between corresponding data points ofthe first set of elevation data points and the second set of elevationdata points; and means for generating an automated report displaying thecomparison, the report defining a high spot or a low spot on theexisting surface when an elevation difference exists betweencorresponding data points of the first set of elevation data points andthe second set of elevation data points.
 12. The apparatus of claim 11,wherein the existing surface includes at least one of a subgrade or aconcrete pavement surface in a plastic state.
 13. The apparatus of claim11, further comprising: means for deriving the intended surface at leastin part from at least one of a string line elevation profile or threedimensional theoretical elevation data.
 14. The apparatus of claim 11,wherein the existing surface is a subgrade.
 15. The apparatus of claim14, further comprising: means for deriving the intended surface at leastin part from at least one of a string line elevation profile or threedimensional theoretical elevation data, and wherein the report indicatesa surface irregularity in the subgrade to be corrected prior tointroducing a paving material to the subgrade.
 16. The apparatus ofclaim 14, further including: means for receiving a user input regardingat least one of a length, a width, or a depth of a pavement portion toform onto the subgrade.
 17. The apparatus of claim 16, furtherincluding: means for calculating a design volume of the pavementportion; and means for determining a predicted volume difference betweenthe design volume and a volume between the subgrade and the intendedsurface.
 18. The apparatus of claim 11, further including: means forestablishing a communicative connection with a source of the first setof elevation data points.
 19. The apparatus of claim 18, wherein themeans for communicative connection includes a wireless networkconnection.
 20. The apparatus of claim 11, wherein the means forreceiving a first set of elevation data points includes: means foruploading a first set of elevation data points from a memory of a sourceof the first set of elevation data points.
 21. A method for analyzingroadway information, comprising: receiving a first set of elevation datapoints defining at least a portion of a concrete surface in a plasticstate; receiving a second set of elevation data points defining at leasta portion of an intended surface, the intended surface being derivedfrom at least one of a string line elevation profile or threedimensional theoretical elevation data; receiving at least one angle ofincidence corresponding to the first set of elevation data points;adjusting the first set of elevation data points based on the at leastone angle of incidence to ensure that the first set of elevation datapoints and second set of elevation data points correspond tosubstantially parallel planes; comparing, via a computer processingdevice, the first set of elevation data points to the second set ofelevation data points to determine whether an elevation differenceexists between corresponding data points of the first set of elevationdata points and the second set of elevation data points, where a datapoint of the first set of elevation data points is a corresponding datapoint to a data point of the second set of elevation data points whenthe data point of the first set of elevation data points and the datapoint of the second set of elevation data points has a same x and ycoordinate of a horizontal plane; storing a comparison of the first setof elevation data points to the second set of elevation data points whenit is determined that an elevation difference exists betweencorresponding data points of the first set of elevation data points andthe second set of elevation data points; and generating an automatedreport displaying the comparison, the report defining at least one of(a) a high spot or a low spot on the existing surface when an elevationdifference exists between corresponding data points of the first set ofelevation data points and the second set of elevation data points or (b)a yield of concrete to provide the existing surface as compared to ayield of concrete to provide the intended surface.